10
Torque Requirements for Caps and
Fasteners
When servicing or repairing HVAC components, ensure
the fasteners are appropriately tightened. “Table 1. Torque
Requirements” on page 10 provides torque values for
fasteners.
IMPORTANT
Only use Allen wrenches of sufficient hardness (50Rc
- Rockwell Harness Scale minimum). Fully insert the
wrench into the valve stem recess.
Service valve stems are factory-torqued from 9 ft.-lbs.
(12 N) for small valves, to 25 ft.-lbs. (34 N) for large
valves) to prevent refrigerant loss during shipping and
handling. Using an Allen wrench rated at less than 50Rc
risks rounding or breaking off the wrench, or stripping
the valve stem recess.
See the Lennox Service and Application Notes C-08-1
for further details and information.
Table 1. Torque Requirements
Parts
Recommended Torque
U.S.
Newton-Meter- N
Service valve cap
8 ft.-lb.
11
Sheet metal screws
16 in.-lb.
2
Machine screws #10
27 in.-lb.
3
Compressor bolts
7 ft.-lb.
10
Gauge port seal cap
8 ft.-lb.
11
Indoor Unit Installation
CAUTION
In order to avoid injury, take proper precaution when
lifting heavy objects.
Unit Placement Considerations
AVOID
Do not install the unit in the following locations:
• Areas exposed to petrochemicals or petrochemical
products
• Areas exposed to salt or other corrosive materials or
caustic gases
• Areas exposed to extreme voltage variations (such as
factories
• Tightly enclosed areas that may impede service of the
unit
• Areas exposed to fossil fuels (such as oil or gas in
kitchens)
• Areas exposed to strong electromagnetic forces
• Areas exposed to acids or alkaline detergents
DO
• Place the unit so that it is not exposed to direct sunlight
• Ensure the structural ceiling can support the weight of
the unit
• Select a location where the condensate line will have
the shortest run to a suitable drain per local codes.
•
Allow sufficient space around unit for proper operation
and maintenance
• Install unit a minimum of 3 feet (1m) away from any
antenna, power cord (line) radio, telephone, security
system, or intercom. Electrical interference and radio
frequencies from any of these sources may affect op-
eration
•
Be sure to instruct customers how to properly operate
the unit (especially maintenance of air filter, and oper
-
ation procedure) by having them carry out operations
themselves while looking at the manual provided with
the controller
Installation of Cassette Base
It is important to place the cassette unit in the center of the
area that is being conditioned. This will provide the best air
distribution.
1. If the unit is to be installed in an application that
includes a drop-down tile ceiling, remove the ceiling
tiles necessary to accommodate installation of the
four-way cassette. Before removing the drop ceiling
support grid, use a plumb line or laser device to
identify the center point of the structural ceiling. Make
sure that the ceiling is supported before removing any
of the support grid. It may be necessary to add extra
support to maintain the structural integrity of the drop
ceiling.
2. If the unit is to be installed in an application that includes
a sheet rock (plasterboard) ceiling, the installation site
must be carefully measured and the sheet rock must
be cut to accommodate the cassette unit. First, identify
the center point of the installed cassette. Use a plumb
line to transfer the center mark to the floor for future
use. Use the provided template to mark the area of the
required opening. Carefully cut the required opening.
Make sure that the removal of the required ceiling
support does not affect the structural integrity of the
ceiling. It may be necessary to add extra support.
3. Use the unit as a template or use the provided paper
template to mark the location of the hanging brackets
on the floor. Use a plumb line or a laser to transfer the
bracket positions to the main structural ceiling.
4. Make sure that the structural ceiling is able to support
the weight of the cassette unit. It may be necessary to
add extra support. If the structural ceiling is constructed
of concrete, install anchors to accept four ⅜” threaded
rods to suspend the cassette base. If the structural
ceiling includes wooden joists, use angle iron or a
